What is wrong in my script, tell me please - linux

Question

I need that scipt enter in my router on page and find the code and compared with earlier this IP information recorded, and if not changed, then stop the script.
I run this script - $ perl ~/test.pl
no error, but file my_ip.txt is not created.
In originals script must check my ip through host example.dyndns.org, but my ip is gray.
So I need to be determined through a router
#!/usr/bin/perl
use LWP::UserAgent;
my $routeraddress = `addr admin:Tavolzhansky#192.168.1.1/RST_conn_status.htm`;
if ($routeraddress =~ /var info_get_wanip="((\d+\.){3}(\d+))"/) {
my $ip = "$1.$2.$3.$4";
#Добавлено:
open (FILE,"my_ip.txt");
my #lines = <FILE>;
$old_ip = $lines[0]; #Считываем IP из файла
$old_ip =~ s/^\s+|\s+$//g; #trim
close(FILE);
if ($old_ip eq $ip) {
die "IP not changed"; # Выходим из скрипта, если IP не изменился
}
open (FILE,">my_ip.txt");
print FILE $ip; # Записываем в файл новый IP
close(FILE);
...... (this code is OK)
}
Do not bring the end of the code because the problem by connecting to the router

Answer 1

$ perl -cw -e 'print `addr admin:foo#192.168.1.1/bar`'
Possible unintended interpolation of #192 in string at -e line 1.
-e syntax OK
It doesn't work because #192 is interpolated as an array, and you are running the command addr admin:Tavolzhansky.168.1.1/RST_conn_status.htm instead of the command you meant to.
This would have been very easy to spot and fix if you would use warnings, if you would step through the code with the debugger, or as Andy suggests, if you would examine return values.
To get #192 to not be interpolated, escape the #:
my $routeraddress = `addr admin:Tavolzhansky\#192.168.1.1/RST_conn_status.htm`;

Answer 2

It's not working because of this:
my $routeraddress = `addr admin:Tavolzhansky#192.168.1.1/RST_conn_status.htm`;
if ($routeraddress =~ /var info_get_wanip="((\d+\.){3}(\d+))"/) {
...
}
Try adding a couple debug prints to confirm like:
my $routeraddress = `addr admin:Tavolzhansky#192.168.1.1/RST_conn_status.htm`;
print "Router IP = $routeraddress/n";
if ($routeraddress =~ /var info_get_wanip="((\d+\.){3}(\d+))"/) {
...
} else {
print "Router address didn't match.\n";
}
You should use the strict and warning pragmas, but as you said this worked when you were getting your IP from a different source, the rest of the code will work.
I'm guessing you're reading an HTML page and expecting to see this string somewhere:
var info_get_wanip="xxx.xxx.xxx.xxx";
However, you need to confirm if $routeraddress is actually getting that, it looks like
my $routeraddress = `addr admin:Tavolzhansky#192.168.1.1/RST_conn_status.htm`;
Is just essentially making a get request for the page, but isn't returning "var info_get_wanip="xxx.xxx.xxx.xxx";". If you sort the assignment of the variable $routeraddress, then it'll work.
I can't say how, as I don't know what it's returning now.